managing hazardous materials incidents - agency for toxic ... › mhmi-v2-2.pdf · hazardous...

30
Section II. Emergency Department Response to Hazardous Materials Incidents HAZARD RECOGNITION When dispatched to the scene of an incident, emergency response personnel may not be aware that the situation involves hazardous materials. As a result, emergency department personnel should always be alert to the possibility that they may be dealing with a chemically contaminated individual, and they should ask incident victims and prehospital personnel about the nature of the event. Emergency departments should also be prepared for exposed patients who arrive unannounced in privately-owned vehicles. Patients may also originate from situations occurring within the hospital. An injury at a hazardous materials incident need not invariably involve chemical exposure: it could have resulted from a physical accident, such as slipping off a ladder. But as a routine precaution, the involvement of hazardous materials should be considered a possibility in such situations. The manual Recognizing and Identifying Hazardous Materials (produced by the National Fire Academy and the National Emergency Training Center) states that there are six primary clues that may signify the presence of hazardous materials. These clues are included below to facilitate and expedite the prompt and correct identification of any hazardous materials at the scene of an incident. Hospital emergency department personnel who are familiar with these clues will find their communication with field personnel enhanced. For example, patient symptoms reported from the field such as nausea, dizziness, itching and burning eyes or skin, or cyanosis could suggest to hospital staff the presence of hazardous materials. They could then request field personnel to examine the site for these six clues: ò Occupancy and Location. Community preplanning should identify the specific sites that contain hazardous materials. In addition, emergency personnel should be alert to the obvious locations in their communities that use and/or store hazardous materials (e.g., laboratories, factories, farm and paint supply outlets, construction sites). The Department of Labor s Material Safety Data Sheets (MSDSs) should also be available, especially for any particularly dangerous chemicals kept on site. It should be kept in mind, however, that these data sheets may have incomplete information and that the medical information provided is generally at a basic first aid level. ò Container Shape. Department of Transportation (DOT) regulations delineate container specifica- tions for the transport of hazardous materials. There are three categories of packaging: stationary bulk storage containers at fixed facilities that come in a variety of sizes and shapes; bulk trans- port vehicles, such as rail and truck tank cars, that vary in shape depending upon the cargo; and labeled fiberboard boxes, drums, or cylinders for smaller quantities of hazardous materials. The shape and configuration of the container can often be a useful clue to the presence of hazardous materials. 11

Upload: others

Post on 27-Jun-2020

2 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Section II. Emergency Department Response to Hazardous Materials Incidents

HAZARD RECOGNITION

When dispatched to the scene of an incident, emergency response personnel may not be aware that

the situation involves hazardous materials. As a result, emergency department personnel should

always be alert to the possibility that they may be dealing with a chemically contaminated individual,

and they should ask incident victims and prehospital personnel about the nature of the event.

Emergency departments should also be prepared for exposed patients who arrive unannounced in

privately-owned vehicles. Patients may also originate from situations occurring within the hospital.

An injury at a hazardous materials incident need not invariably involve chemical exposure: it could

have resulted from a physical accident, such as slipping off a ladder. But as a routine precaution, the

involvement of hazardous materials should be considered a possibility in such situations. The manual

Recognizing and Identifying Hazardous Materials (produced by the National Fire Academy and the

National Emergency Training Center) states that there are six primary clues that may signify the

presence of hazardous materials. These clues are included below to facilitate and expedite the

prompt and correct identification of any hazardous materials at the scene of an incident. Hospital

emergency department personnel who are familiar with these clues will find their communication

with field personnel enhanced. For example, patient symptoms reported from the field such as

nausea, dizziness, itching and burning eyes or skin, or cyanosis could suggest to hospital staff the

presence of hazardous materials. They could then request field personnel to examine the site for

these six clues:

ò Occupancy and Location. Community preplanning should identify the specific sites that contain

hazardous materials. In addition, emergency personnel should be alert to the obvious locations in

their communities that use and/or store hazardous materials (e.g., laboratories, factories, farm and

paint supply outlets, construction sites). The Department of Labor s Material Safety Data Sheets

(MSDSs) should also be available, especially for any particularly dangerous chemicals kept on

site. It should be kept in mind, however, that these data sheets may have incomplete information

and that the medical information provided is generally at a basic first aid level.

ò Container Shape. Department of Transportation (DOT) regulations delineate container specifica­

tions for the transport of hazardous materials. There are three categories of packaging: stationary

bulk storage containers at fixed facilities that come in a variety of sizes and shapes; bulk trans­

port vehicles, such as rail and truck tank cars, that vary in shape depending upon the cargo; and

labeled fiberboard boxes, drums, or cylinders for smaller quantities of hazardous materials. The

shape and configuration of the container can often be a useful clue to the presence of hazardous

materials.

11

Page 2: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

ò Markings/Colors. Certain transportation vehicles must use DOT markings, including identification

(ID) numbers. Identification numbers, located on both ends and both sides, are required on all cargo

tanks, portable tanks, rail tank cars, and other packages that carry hazardous materials. Railcars

may have the names of certain substances stenciled on the side of the car. A marking scheme

designed by the National Fire Protection Association (NFPA 704M System) identifies hazard

characteristics of materials at terminals and industrial sites, but does not provide product-specific

information. This system uses a diamond divided into four quadrants. Each quadrant represents

a different characteristic: the left, blue section refers to health; the top, red quarter pertains to flam­

mability; the right, yellow area is for reactivity; and the bottom, white quadrant highlights special

information (e.g., W indicates dangerous when wet, Oxy stands for oxidizer). A number from

zero through four in each quadrant indicates the relative risk of the hazard, with zero representing

the minimum risk. This system does not indicate what the product is, the quantity, or its exact

location. In addition, it does not reveal the compound s reactivity with other chemicals. The mili­

tary also uses distinctly shaped markings and signs to designate certain hazards. These markings

may be found on vehicles, on the products themselves, or on shipping papers.

ò Placards/Labels. These convey information through use of colors, symbols, Hazard Communication

Standards, American National Standard Institute (ANSI) Standards for Precautionary Labeling of

Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class

wording or four-digit identification numbers. Placards are used when hazardous materials are

being stored in bulk (usually over 1,001 lb), such as in cargo tanks. Labels designate hazardous

materials kept in smaller packages. Caution must be exercised, however, because the container or

vehicle holding a hazardous material may be improperly labeled or recorded, or it may not have

any exterior warning.

ò Shipping Papers. Shipping papers can clarify what is labeled as dangerous on placards.

They should provide the shipping name, hazard class, ID number, and quantity, and may indicate

whether the material is waste or poison. Shipping papers, which must accompany all hazardous

material shipments, are now required to list a 24-hour emergency information telephone number.

The location where the shipping papers are stored can be problematical; often they are found in

close proximity to the hazardous material(s) or in other locations not easily accessible during an

emergency. Shipping papers should remain at the incident scene for use by all response personnel.

ò Senses. Odor, vapor clouds, dead animals or fish, fire, and skin or eye irritation can signal the

presence of hazardous materials. Generally, if one detects an odor of hazardous materials, it

should be assumed that exposure has occurred and the individual is still in the danger area,

although some chemicals have a detectable odor at levels below their toxic concentrations. Some

chemicals, however, can impair an individual s sense of smell (e.g., hydrogen sulfide), and others

have no odor, color or taste at all (e.g., carbon monoxide). Binoculars are helpful to ascertain

visible information from a safe distance.

12

Page 3: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Appendix A provides greater detail on the NFPA s 704M system; the DOT s hazardous materials

marking, labeling, and placarding guide; and the Department of Labor s MSDS. It is important that

any and all available clues are used in substance identification, especially obvious sources such as

the information provided on a label or in shipping papers.

The aim of the health provider should be to make a chemical-specific identification while exercising

caution to prevent exposure to any chemicals. Identifying the hazardous material and obtaining

information on its physical characteristics and toxicity are vital steps to the effective management of

a hazardous materials incident. Since each compound has its own unique set of physical and toxico­

logical properties, early and accurate identification of the hazardous material(s) involved allows

emergency personnel to initiate appropriate management steps.

Many resources are available to provide information concerning response to and planning for

hazardous materials incidents. All such information, however, needs to be interpreted with respect

to the specific release scenario. A selected bibliography of written material is included at the end

of each section of this guidebook; it is not, however, a complete list of the materials available.

Printed reference materials provide several advantages: they are readily available, they can be

kept in the response vehicle, they are not dependent on a power source or subject to malfunction,

and they are relatively inexpensive. Disadvantages include the difficulty of determining the cor­

rect identity for an unknown chemical through descriptive text, the logistics of keeping the mate­

rials current, and the problem that no single volume is capable of providing all the information

that may be needed.

There is also a vast array of telephone and computer-based information sources concerning hazardous

materials. They can help by describing the toxic effects of a chemical, its relative potency, and the

potential for secondary contamination. They may also recommend decontamination procedures,

clinical management strategies, and advice on the adequacy of specific types of protective gear.

Exhibit II-1A is a partial listing of the many information resources available by telephone. Exhibit

II-1B is a list of suggested telephone numbers that should be filled in for your community, including

the regional Poison Control Center, which is a ready source of information 24 hours a day. Exhibit

II-2 provides a partial listing of computerized and online information sources. Note, however, that

not all online databases are peer reviewed; for example, some medical management information may

be based only on DOT or MSDS data. Care and planning should be used when selecting information

sources. Planning is an essential part of every response, and many of these resources can provide

guidance in the formation of an effective response plan.

13

Page 4: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-1A Telephone Information and Technical Support References

Resource Contact Services Provided

Chemical Transportation Emergency Center

(CHEMTREC) 1-800-424-9300 24-hour emergency number connecting with

manufacturers and/or shippers. Advice

provided on handling, rescue gear,

decontamination considerations, etc.

Also provides access to the Chlorine

Emergency Response Plan (CHLOREP).

Agency for Toxic Substances and Disease Registry

(ATSDR) 1-404-639-6360 24-hour emergency number for health-

related support in hazardous materials

emergencies, including onsite assistance.

Bureau of Explosives 1-719-585-1881 Contact number for technical questions about

railway transport of hazardous materials.

For emergencies, call CHEMTREC

(1-800-424-9300).

Emergency Planning and Community 1-800-424-9346 Available 9:00 a.m. to 6:00 p.m. (EST).

Right-to-Know Act (EPCRA) and Provides information on SARA Title III,

Resource Conservation and Recovery Act (RCRA) list of extremely hazardous substances,

Information Hotline and planning guidelines.

Environmental Protection Agency (EPA) website: Environmental response teams

Regional Offices www.epa.gov/regional available for technical assistance.

Region I (CT, ME, MA, NH, RI, VT) 1-617-918-1111

Region II (NJ, NY, PR, VI) 1-212-637-3000

Region III (DE, DC, MD, PA, VA, WV) 1-215-814-2900;

intra-regional only:

1-800-438-2474

Region IV (AL, FL, GA, KY, MS, NC, SC, TN) 1-404-562-9900;

Emergency Response &

Removal Branch:

1-800-564-7577

Region V (IL, IN, MI, MN, OH, WI) 1-312-353-2000

Region VI (AR, LA, NM, OK, TX) 1-214-665-2200

Region VII (IA, KS, MO, NE) 1-913-551-7003

Region VIII (CO, MT, ND, SD, UT, WY) 1-303-312-6312

Region IX (AZ, CA, HI, NV; 1-415-744-1500;

Pacific Islands AS, FM, GU, MH, MP, PW) emergencies:

1-415-744-2000

Region X (AK, ID, OR, WA) 1-206-553-1200

14

Page 5: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-1A (continued)

Resource Contact Services Provided

National Animal Poison Control Center 1-800-548-2423

1-888-426-4435

24-hour consultation services concerning

animal poisonings or chemical contami

nation. Provides an emergency response

team to investigate incidents and to

perform laboratory analysis.

-

National Pesticides Information

Retrieval System (NPIRS)

1-765-494-6616

website:

ceris.purdue.edu/npirs

Contact information for help in searching

NPIRS database to get fact sheets on

pesticides, insecticides, fungicides, and

state and federally registered chemicals.

National Pesticide Telecommunications

(NPTN)

(Oregon State University)

1-800-858-7378

website:

ace.orst.edu/info/nptn

Provides information about pesticide-Network

related topics, including pesticide

products, recognition and management

of pesticide poisoning, toxicology,

environmental chemistry, referrals for

laboratory analyses, investigation of

pesticide incidents, emergency

treatment, safety, health and environmental

effects, cleanup, and disposal procedures.

National Response Center 1-800-424-8802 A federal hotline for reporting oil and

chemical spills where hazardous materials

are responsible for death, serious injury,

property damage in excess of $50,000, or

continuing danger to life and property.

U.S. Army Soldier and Biological

Chemical Command (SBCCOM)

1-800-368-6498 24-hour consultation service for threats

and releases pertaining to chemical and

biological agents.

15

Page 6: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-1B Local Telephone Information and Technical Support Resource Worksheet

Resource Contact Services Provided (fill in for future reference) (fill in for future reference)

EPA Regional or State Office

Regional Poison Control Center

State Emergency Response Commission

State Health Department

State Emergency Management Office

Local Fire Department

Local Hazardous Materials

Response Team

Community Police Department

Local Emergency Planning Committee

Local Health Department

State Department of Natural Resources

FEMA Regional Office

State Agriculture Office

State Lab Office

State EMS Office

Hyperbaric Medicine Chamber

Burn Center

CDC

U.S. Army Soldier and Biological Chemical Command

16

Page 7: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-2 Computerized Data Sources for Information and Technical Support

Data System Contact Description

CAMEO CAMEO Database Manager

7600 Sand Point Way, N.E.

Seattle, Washington 98115

(206) 526-6317

website: www.epa.gov/ceppo/cameo

CHRIS CIS, Inc.

c/o Oxford Molecular Group

11350 McCormick Road

Executive Plaza, Suite 1100

Hunt Valley, Maryland 21031

(800) 247-8737

website: www.oxmol.com/software/cis/

details/CHRIS.shtml

HAZARDTEXT Micromedex, Inc.

Suite 300

6200 S. Syracuse Way

Englewood, Colorado 80111-4740

(800) 525-9083

website: www.micromedex.com/products/

pd-main.htm

HMIS Kevin Coburn

Information Systems Manager

U.S. Department of Transportation

D.H.M. 63 - Room 8104

400 7th Street SW

Washington, D.C. 20590-0001

website: www.dlis.dla.mil/hmis.htm

HSDB HSDB Representative

National Library of Medicine

Specialized Information Systems

8600 Rockville Pike

Bethesda, Maryland 20894

(301) 496-6531

website: sis.nlm.nih.gov/sis1

Computer-aided management of National

Oceanic and Atmospheric Administration

(NOAA) operations available to on-scene

responder(s). Chemical identification

database assists in Hazardous Materials

Response Division determining substance(s)

involved, predicting downwind

concentrations, providing response

recommendations, and identifying potential

hazards.

Chemical Hazard Response Information

System, developed by the Coast Guard and

comprised of reviews on fire hazards,

fire-fighting recommendations, reactivities,

physicochemical properties, health hazards,

use of protective clothing, and shipping

information for over 1,000 chemicals.

Assists responders dealing with incidents

involving hazardous materials, such as spills,

leaks, and fires. Provides information on

emergency medical treatment and

recommendations for initial hazardous

response.

Hazardous Material Information Systems

contains information on hazardous materials.

Transportation-related incidents may be

reported on DOT form 5800.1 (Hazardous

Materials Incident Report Form).

Hazardous Substances Data Bank, compiled

by the National Library of Medicine,

provides reviews on the toxicity, hazards, and

and regulatory status of over 4,000 frequently

used chemicals.

17

Page 8: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-2 (continued)

Data System Contact Description

1st MEDICAL RESPONSE Micromedex, Inc. Helps develop training programs and establish

PROTOCOLS Suite 300 protocols for first aid or initial workplace

6200 S. Syracuse Way response to a medical emergency.

Englewood, Colorado 80111

(800) 525-9083

website: www.micromedex.com/products/

pd-main.htm

MEDITEXT Micromedex, Inc. Provides recommendations regarding the

Suite 300 evaluation and treatment of exposure to

6200 S. Syracuse Way industrial chemicals.

Englewood, Colorado 80111

(800) 525-9083

website: www.micromedex.com/products/

pd-main.htm

OHMTADS Oxford Molecular Group, Inc. Oil and Hazardous Materials/Technical

11350 McCormick Rd. Assistance Data Systems provides information

Executive Plaza 3, Suite 1100 on the effects of spilled chemical compounds

Hunt Valley, Maryland 21031 and their hazardous characteristics and

(800) 247-8737 properties, assists in identifying unknown

website: www.oxmol.com/software/cis/ substances, and recommends procedures for

details/OHMTADS.shtml handling cleanups.

TOMES Micromedex, Inc. The Tomes Plus Information Systems is a series

Suite 300 of comprehensive databases on a single

6200 S. Syracuse Way CD-ROM disc. It provides information

Englewood, Colorado 80111 regarding hazardous properties of chemicals

(800) 525-9083 and medical effects from exposure. The Tomes

website: www.micromedex.com/products/ Plus database contains Meditext, Hazardtext,

pd-main.htm HSBD, CHRIS, OHMTADS, and 1st Medical

Response Protocols.

TOXNET Toxicology Data Network (TOXNET) A computerized system of three toxicologically

National Library of Medicine oriented data banks operated by the National

Specialized Information Services Library of Medicine the Hazardous

8600 Rockville Pike Substances Data Bank, the Registry of Toxic

Bethesda, Maryland 20894 Effects of Chemical Substances, and the

(301) 496-6531 Chemical Carcinogenesis Research Information

website: sis.nlm.nih.gov/sis1 System. TOXNET provides information on the

health effects of exposure to industrial and

environmental substances.

18

Page 9: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

PRINCIPLES OF TOXICOLOGY FOR EMERGENCY DEPARTMENT PERSONNEL

Exposure to hazardous chemicals may produce a wide range of adverse health effects. The likelihood

of an adverse health effect occurring, and the severity of the effect, are dependent on: (1) the toxicity of

the chemical; (2) the route of exposure; (3) the nature and extent of exposure; and (4) factors that

affect the susceptibility of the exposed person, such as age and the presence of certain chronic diseases.

To better understand potential health effects, emergency department personnel should understand the

basic principles and terminology of toxicology.

Toxicology is the study of the nature, effects, and detection of poisons in living organisms. Examples of

these adverse effects, sometimes called toxic end points, include carcinogenicity (development of can­

cer), hepatotoxicity (liver damage), neurotoxicity (nervous system damage), and nephrotoxicity (kid­

ney damage). This is merely a sample list of toxic end points that might be encountered (Exhibit II-3).

Toxic chemicals often produce injuries at the site which they come into contact with the body. A

chemical injury at the site of contact, typically the skin and the mucous membranes of the eyes,

nose, mouth, or respiratory tract, is termed a local toxic effect. Irritant gases such as chlorine and

ammonia can, for example, produce a localized toxic effect in the respiratory tract, while corrosive

acids and bases can result in local damage to the skin. In addition, a toxic chemical may be absorbed

into the bloodstream and distributed to other parts of the body, producing systemic effects. Many

Exhibit II-3 Examples of Adverse Health Effects from Exposure to Toxic Chemicals

Toxic End Point Target Organ Example of Health Effect Health Effect Systems Causative Acute Chronic

Agent

Carcinogenicity Multiple sites Benzene Dermatitis Acute myelogenous

Chest tightness

leukemia

Dizziness

Headache

Hepatotoxicity Liver Carbon tetrachloride Vomiting Liver necrosis

Abdominal pain

Fatty liver

Dizziness

Rash

Neurotoxicity Nervous system Lead Nausea Wrist drop

Vomiting

IQ deficits

Abdominal pain

Encephalopathy

Nephrotoxicity Kidney Cadmium Vomiting Kidney damage

Diarrhea

Anemia

Chest pain

19

Page 10: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

pesticides, for example, are absorbed through the skin, distributed to other sites in the body, and

produce adverse effects such as seizures or cardiac, pulmonary, or other problems. It is important for

medical providers to recognize that exposure to chemical compounds can result not only in the

development of a single systemic effect but also in the development of multiple systemic effects or a

combination of systemic and local effects. Some of these effects may be delayed, sometimes for as

long as 48 or more hours. Health effects can also be acute or chronic. Acute health effects are short-term

effects that manifest within hours or days, such as vomiting or diarrhea. Chronic health effects are

long-term effects that may take years to manifest, such as cancer.

Routes and Extent of Exposure

There are three main routes of chemical exposure: inhalation, dermal contact (with skin or mucous

membranes), and ingestion. Inhalation results in the introduction of toxic compounds into the respi­

ratory system, and potentially into the bloodstream. Most of the compounds that are commonly

inhaled are gases or vapors of volatile liquids. However, solids and liquids can be inhaled as dusts or

aerosols. Inhalation of toxic agents generally results in a rapid and effective absorption of the compound

into the bloodstream because of the large surface area of the lung tissue and number of blood vessels

in the lungs. Knowing a chemical s vapor pressure (VP) can be useful in determining the inhalation

risk for a particular exposure. The lower the VP, the less likely the chemical will produce an inhalable

gas and vice versa. Water solubility is also an important contributor for symptom development.

Irritant agents that are water soluble usually cause early upper respiratory tract irritation, resulting in

coughing and throat irritation. Partially water-soluble chemicals penetrate into the lower respiratory

system causing delayed symptoms (12 to 24 h) which include trouble breathing, pulmonary edema,

and coughing up blood. Asphyxiants are chemicals that impede the body s ability to obtain or utilize

oxygen. Simple asphyxiants are inert gases (e.g., argon, propane, nitrogen) that displace oxygen in

inspired air. Chemical asphyxiants produce harm by preventing oxygen delivery or utilization for

energy production by the body s cells. Carbon monoxide and cyanide are examples of asphyxiants.

Dermal contact does not typically result in as rapid absorption as inhalation, although some chemicals

are readily taken in through the skin. Many organic compounds are lipid (fat) soluble and can therefore

be rapidly absorbed through dermal exposure. Some materials that come in contact with the eyes can

also be absorbed.

Ingestion is a less common route of exposure for emergency response personnel at hazardous materials

incidents. However, incidental hand-to-mouth contact, smoking, and swallowing of saliva and

mucus that contains contaminants may also result in exposure by this route. In addition, emergency

medical personnel in both hospital or prehospital settings treat chemical exposures in patients who

have ingested toxic substances as a result of accidental poisonings or suicide attempts.

Compounds may also be introduced into the body through injection, although this is an unlikely

route of exposure in spills or discharges of hazardous materials. Explosions may result in injection

injuries and lead to imbedded foreign bodies, which may themselves be chemically contaminated.

The route by which personnel are exposed to a compound plays a role in determining the total amount

of the substance taken up by the body because a compound may be absorbed by one route more readily

than by another. In addition, the route of exposure may affect the nature of the symptoms that develop.

The amount of the compound absorbed by the body also depends on the duration of exposure and the

concentration of the compound to which one is exposed.

20

Page 11: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

It is important to recognize that children may be more susceptible to many toxic exposures, in part

because they are likely to receive a higher dose relative to body weight than an adult. This occurs

for a number of reasons. First, children are shorter than adults and since most toxic gases are heavier

than air, the concentrations increase as you get closer to the ground. Children s immature central

nervous system, liver, and renal system also increase their susceptibility to injury as a result of

exposure to chemicals. In addition, children have a larger lung surface area relative to their weight

than adults, as well as a greater respiratory volume (liters/min/kg of body weight). It is probable that

the child s lung is a more effective absorbent surface than that of the adult. Children also have a

larger skin area relative to their weight than do adults, allowing more effective surface area for

absorption in dermal exposures. A child s skin is also more easily penetrated by chemicals, allowing

for more rapid and effective dermal absorption. Finally, children are more likely to ingest toxic

chemicals because of increased hand-to-mouth behavior, including pica. All of these factors may

lead to an increased dose relative to size in children as compared to adults, even when they all are

exposed to the same scenario.

A complex relationship exists between the total amount of the compound absorbed by the body

(dose) and the concentration of that compound in the environment. This relationship is important for

emergency medical personnel to understand because the adverse effects produced by a toxic compound

are usually related to the dose of that compound received by a patient. However, because we usually

only monitor the concentration of the toxic substance in the environment (e.g., parts per million

(ppm) of a compound in air), the actual dose of the compound received by the patient is seldom

known. Factors specific to the exposed patient, such as area of skin surface exposed, presence of

open wounds or breaks in the skin, and the rate and depth of respirations, are important in estimating

the dose of the compound received by the patient.

Dose-Response Relationship

The effect produced by a toxic compound is primarily a function of the dose of the compound. This

principle, termed the dose-response relationship, is a key concept in toxicology. Many factors affect

the normal dose-response relationship and they should be considered when attempting to extrapolate

toxicity data to a specific situation (Exhibit II-4).

Typically, as the dose increases, the severity of the toxic response increases. Humans exposed to 100

ppm of tetrachloroethylene, a solvent that is commonly used for dry-cleaning fabrics, may experi­

ence relatively mild symptoms, such as headache and drowsiness. However, exposure to 200 ppm

tetrachloroethylene can result in a loss of motor coordination in some individuals, and exposure to

1,500 ppm for 30 minutes may result in a loss of consciousness (Exhibit II-5). As shown in Exhibit

II-5, the severity of the toxic effect also depends on the duration of exposure, a factor that influences

the dose of the compound in the body.

21

Page 12: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-4 Classification of Factors Influencing Toxicity

Type Examples

Factors related to the chemical Composition (salt, freebase, etc.); physical characteristics

(size, liquid, solid, etc.); physical properties (volatility, solubility, etc.);

presence of impurities; breakdown products; carriers

Factors related to exposure Dose; concentration; route of exposure (inhalation, ingestion, dermal);

duration

Factors related to the exposed person Heredity; immunology; nutrition; hormones; age; sex; health status;

preexisting diseases; pregnancy

Factors related to environment Media (air, water, soil, etc.); additional chemicals present;

temperature; humidity; air pressure; and fire

Exhibit II-5 Dose-Response Relationship for Humans Inhaling Tetrachloroethylene Vapors

Levels in Air Duration of Exposure Effects on Nervous System

50 ppm Odor threshold

100 ppm 7 hours Headache, drowsiness

200 ppm 2 hours Dizziness, uncoordination

600 ppm 10 minutes Dizziness, loss of inhibitions

1,000 ppm 1-2 minutes Marked dizziness, intolerable eye and

respiratory tract irritation

1,500 ppm 30 minutes Coma

22

Page 13: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Toxicity information is often expressed as the dose of a compound that causes an effect in a percentage

of the exposed subjects, which are usually experimental animals. These dose-response terms are

often found in the Material Safety Data Sheets (MSDSs) and other sources of health information.

One dose-response term that is commonly used is the lethal dose 50 (LD50). This is the dose that is

lethal to 50 percent of an animal population from exposure by a specific route (except inhalation)

when given all in one dose. A similar term is the lethal concentration 50 (LC50), which is the con­

centration of a material in air that on the basis of respiratory exposure in laboratory tests is expected

to kill 50 percent of a group of test animals when administered as a single exposure (usually 1 hour).

Exhibit II-6 lists a number of chemicals that may be encountered in dealing with hazardous materials

incidents, and the reported acute LD50 values of these compounds when they are administered by

ingestion to rats.

From Exhibit II-6 it can be seen that a dose of 3,000 to 3,800 mg/kg tetrachloroethylene is lethal to

50 percent of rats that received the compound orally; however, only 6.4 to 10 mg/kg of sodium

cyanide is required to produce the same effect. Therefore, compounds with low LD50 values are

more acutely toxic than substances with higher LD50 values.

The LD50 values that appear in an MSDS or in the literature must be used with caution by emergency

medical personnel. These values are an index of only one type of response and give no indication of

the ability of the compound to cause nonlethal, adverse or chronic effects. They also do not reflect

possible additive effects from the mixture of chemicals sometimes found with exposure to hazardous

materials. Furthermore, LD50 values typically come from experimental animal studies. Because of

the anatomical and physiological differences between animals and humans, it is difficult to compare

the effects seen in experimental animal studies to the effects expected in humans exposed to hazardous

materials in the field. LC50 and LD50 values are also usually determined in healthy adult animals.

Values determined in young animals may be quite different, as may values determined in animals

with an underlying disease. It is known that many chemicals are more toxic (lower LD50 or LC50

values) in young or newborn animals than in adults. This same age dependence may exist in

humans. Because several organs, particularly the brain, are still developing in young children, damage

to these organs may be more extensive and can be permanent. Also, infants may not be able to

excrete chemicals from the body as efficiently as adults because their kidneys and liver are not fully

developed. This may lead to longer and greater exposure to the chemical than would occur in an

adult with the same relative exposure. The immaturity of metabolizing enzymes in the liver may

lead to either increased or decreased toxicity in infants relative to adults. Which may occur is diffi­

cult to predict for many chemicals. Therefore, emergency medical personnel should remember that

the LD50 and LC50 values are only useful for comparing the relative approximate toxicity of com­

pounds.

23

Page 14: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-6 Acute LD50 Values for Representative Chemicals When

Administered Orally to Rats

Chemical

Sodium cyanide

Acute Oral LD50 (mg/kg)1

6.4-10

Pentachlorophenol 50-230

Chlordane 83-560

Lindane 88-91

Toluene 2,600-7,000

Tetrachloroethylene 3,000-3,800

1 Milligrams of the compound administered per kilogram body weight of the experimental animal.

Responses to toxic chemicals may differ among individuals because of the physiological variability

that is present in the human population. Some individuals, for example, are more likely to experience

adverse health effects after exposure to a toxic chemical because of a reduced ability to metabolize

that compound. The presence of preexisting medical conditions (e.g., pulmonary, hepatic, or renal

disease, diabetes) can also increase one s susceptibility to toxic chemicals. Respiratory distress in

people with asthma may be triggered by exposure to toxic chemicals at lower concentrations than

might be expected to produce the same effect in individuals without respiratory disease. Factors

such as age, personal habits (e.g., smoking, diet), previous exposure to toxic chemicals, and medica­

tions may also increase an individual s sensitivity to toxic chemicals. Therefore, exposure to concen­

trations of toxic compounds that would not be expected to result in the development of a toxic

response in most people may cause an effect in susceptible individuals. Not all chemicals, however,

have a threshold level. Some carcinogens (cancer-causing chemicals) may produce a response

(tumors) at any dose level, and any exposure to these compounds may be associated with some risk of

developing cancer. Thus, literature values for levels that are not likely to produce an effect do not

guarantee that an effect will not occur.

Exposure Limits

The various occupational exposure limits found in the literature or on an MSDS are based primarily

on time-weighted average limits, ceiling values, or ceiling concentration limits to which the worker

can be exposed without adverse effects. Examples of these limits are listed in Exhibit II-7A.

24

Page 15: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

The values listed in Exhibit II-7A were established to provide worker protection in occupational

settings. Because the settings in which these values are appropriate are quite different than an

uncontrolled spill site, it is difficult to interpret how these values should be used by emergency med­

ical personnel when dealing with a hazardous materials incident. These values are designed for a

healthy adult working population and have limited utility when applied to some of the at risk

groups mentioned previously. At best, TLV, PEL, IDLH, and REL values can be used as benchmarks

for determining relative toxicity, and perhaps to assist in selecting appropriate levels of personal pro­

tective equipment (PPE). Furthermore, these occupational exposure limits are only useful if trained

personnel and appropriate instrumentation are available for measuring the levels of toxic chemicals

in the air at the spill site. Of the occupational exposure limit values shown in Exhibit II-7A, only

the OSHA values are regulatory limits. The ACGIH values are for guidance only and are not regula­

tory limits. In addition, the ACGIH limits have certain caveats that may or may not affect the useful­

ness of the values. Some of these conditions are individual susceptibility or aggravation of a preex­

isting condition. Because of the limitations of PELs and TLVs, special exposure limits have been

established. Emergency Response Planning Guidelines (ERPGs), Short-term Public Emergency

Guidance Levels (SPEGLs), and Acute Exposure Guidelines (AEGLs, under development by the

EPA) have been designed to assist emergency personnel in making decisions regarding nonwork­

place exposures (Exhibit II-7B). Emergency medical personnel responsible for the management of

chemically contaminated patients should be familiar with all of these exposure limits because they will

be encountered in various documents dealing with patient care or the selection of PPE.

This brief discussion highlights some fundamental concepts of toxicology. Emergency medical

personnel responsible for managing chemically contaminated patients are encouraged to obtain

further training in their recognition and treatment. A list of general toxicology references is provided

at the end of this section that will allow emergency medical personnel to undertake a more in-depth

examination of the principles of toxicology.

PERSONNEL PROTECTION AND SAFETY PRINCIPLES

This section provides information on personal protective equipment (PPE) and safety principles to

emergency medical personnel who, because of their proximity to a chemical industrial area or transport

corridor, may be required to treat chemically contaminated patients. In the majority of cases, hospital

staff will not experience incidents involving chemically contaminated patients frequently enough to

keep them optimally trained or their equipment properly maintained. Staff must be initially trained in

the proficient use of PPE, specifically respiratory equipment, and must maintain that proficiency.

According to state and federal regulations, equipment must be maintained according to OSHA

specifications, and respirators and their cartridges have to be properly fitted, tested, and stored.

Many hospitals, given their workload mix and fiscal constraints, may not be able to expend the

funds and time necessary to accomplish this task. In these cases, these hospitals should make

arrangements with the local fire department or hazmat team to be ready, if the situation warrants, to

decontaminate patients, including those who are transported to a hospital before they are decontami­

nated. Considerations in determining what a hospital s capabilities should be include the number of

incidents occurring locally (several per week versus only a few per year) and proximity to industries

or transportation routes that have the potential for a hazardous materials incident (see Section I

SARA Title III).

25

Page 16: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-7A Occupational Exposure Limits

Value Abbreviation Definition

Threshold Limit Value (ACGIH)1 TLV Refers to airborne concentrations of

substances and represents conditions under

which it is believed that nearly all workers

may be repeatedly exposed day after day

without adverse effect.

Threshold Limit Value: TLV-TWA The time-weighted average concentration for a

Time-Weighted Average (ACGIH)1 normal 8-hour work day and a 40-hour work

week, to which nearly all workers may be

repeatedly exposed, day after day, without

adverse effect.

Threshold Limit Value: TLV-STEL The concentration to which workers can be

Short-Term Exposure Limit (ACGIH)1 exposed continuously for a short period of

time without suffering from (1) irritation,

(2) chronic or irreversible tissue damage, or

(3) narcosis of a sufficient degree to increase

the likelihood of accidental injury, to impair

self-rescue, or to materially reduce work

efficiency; and provided that the daily

TLV-TWA is not exceeded.

Threshold Limit Value: TLV-C The concentration that should not be exceeded

Ceiling (ACGIH)1 during any part of the working exposure.

Permissible Exposure Limit (OSHA)2 PEL Same as TLV-TWA.

Immediately Dangerous to Life and Health IDLH A maximum airborne concentration from

(OSHA)2 which one could escape within 30 minutes

without any escape-impairing symptoms or

any irreversible health effects.

Recommended Exposure Limit (NIOSH)3 REL Highest allowable airborne concentration that

is not expected to injure a worker; expressed

as a ceiling limit or time-weighted average for

an 8- or 10-hour work day.

1 American Conference of Governmental Industrial Hygienists

2 Occupational Safety and Health Administration

3 National Institute for Occupational Safety and Health

26

Page 17: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-7B General Population Exposure Limits

Value Abbreviation Definition

Emergency Response Planning Guidelines (AIHA)1 ERPG Maximum airborne concentration below which

it is believed that nearly all individuals could

be exposed for up to 1 hour without

(1) experiencing other than mild transient

adverse health effects or perceiving a clearly

defined objectionable odor (ERPG-1),

(2) experiencing or developing irreversible or

other serious health effects or symptoms that

could impair an individual s ability to take

protective action (ERPG-2), or

(3) experiencing or developing life-threatening

health effects (ERPG-3).

Short-term Public Emergency Guidance Level SPEGL An acceptable concentration for unpredicted,

(NRC)2 single, short-term exposure of the general

public in emergency situations. May be

developed for different exposure periods

(e.g., 1, 2, 4, 8, 16, 24 hours).

Acute Exposure Guidelines (EPA NAC/AEGL)3 AEGL Proposed short-term threshold or ceiling

exposure value intended for the protection of

the general public, including susceptible or

sensitive individuals but not those who are

hypersusceptible or hypersensitive. Represents

the airborne concentration of a substance at or

above which it is predicted that the general

population (as defined above) could experience

(1) notable discomfort (AEGL-1),

(2) irreversible or other serious, long-lasting

effects or impaired ability to escape (AEGL-2),

or (3) life-threatening effects or death

(AEGL-3). Developed for four exposure

periods: 30 minutes, and 1, 4 , and 8 hours.

Synonymous with the NAS4 term,

Community Emergency Exposure Levels

(CEELs).

1 American Industrial Hygiene Association

2 National Research Council

3 EPA National Advisory Committee/AEGL Committee

4 National Academy of Sciences

27

Page 18: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Federal Regulations Pertaining to Use of Personal Protective Equipment (PPE)

The term personal protective equipment (PPE) is used in this document to refer to both clothing and

equipment. The purpose of PPE is to shield or isolate individuals from the chemical, physical, and

biological hazards that may be encountered at a hazardous materials incident.

Training is essential before any individual attempts to use PPE. OSHA standards mandate spe­

cific training requirements (8 hours of initial training or sufficient experience to demonstrate compe­

tency) for personnel engaged in emergency response to hazardous substances incidents at the First

Responder Operations Level. In addition, each employer must develop health and safety programs

and provide for emergency response. These standards also are intended to provide additional protection

for those who respond to hazardous materials incidents, such as firefighters, police officers, and

EMS personnel. OSHA s final rule (March 6, 1989, 29 CFR (1910.120)) as it applies to emergency

medical personnel states: Training shall be based on the duties and functions to be performed by

each responder of an emergency response organization.

No single combination of protective equipment and clothing is capable of protecting against all

hazards. Thus, PPE should be used in conjunction with other protective methods. The use of PPE

can itself create significant worker hazards, such as heat stress, physical and psychological stress,

and impaired vision, mobility, and communication. Responders in PPE can also be frightening to

pediatric patients. In general, the greater the level of PPE protection, the greater are the associated

risks. For any given situation, equipment and clothing should be selected that provide an adequate

level of protection. Excessive protection can be as hazardous as under-protection, and should be

avoided. In addition, personnel should not be expected to use PPE without adequate training.

The two basic objectives of any PPE program should be to protect the wearer from safety and health

hazards and to prevent injury to the wearer from incorrect use and/or malfunction of the PPE. To

accomplish these goals, a comprehensive PPE program should include: (1) hazard identification;

(2) medical monitoring; (3) environmental surveillance; (4) selection, use, maintenance, and decont­

amination of PPE; and (5) training.

PPE Complications

Personnel wearing PPE are likely to encounter a number of potential problems, including limited

visibility, reduced dexterity, claustrophobia, restricted movement, suit breach, insufficient air supply,

dehydration, and the effects of heat and cold. Only individuals who are physically fit and have met

the OSHA/NIOSH/NFPA training requirements should be wearing PPE during an incident. Proper

donning and doffing procedures must be followed, with assistance from other onsite personnel.

Medical surveillance evaluations should be conducted on all individuals both before and immediately

after their use of PPE. The actions of all personnel wearing PPE should also be closely observed by

the safety officer and others during each work period. In addition, an emergency distress signal

should be identified in the briefing before individuals enter the work area.

28

Page 19: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Levels of Protection

EPA has designated four levels of protection to assist in determining which combinations of respira­

tory protection and protective clothing should be employed:

Level A protection should be worn when the highest level of respiratory, skin, eye, and mucous

membrane protection is needed. It consists of a fully-encapsulated, vapor-tight, chemical-resistant

suit, chemical-resistant boots with steel toe and shank, chemical-resistant inner/outer gloves, coveralls,

hard hat, and self-contained breathing apparatus (SCBA).

Level B protection should be selected when the highest level of respiratory protection is needed but

a lesser degree of skin and eye protection is required. It differs from Level A only in that it provides

splash protection through use of chemical-resistant clothing (overalls and long-sleeved jacket, two-

piece chemical splash suit, disposable chemical-resistant coveralls, or fully-encapsulated, non-

vapor-tight suit and SCBA).

Level C protection should be selected when the type of airborne substances is known, concentration is

measured, criteria for using air-purifying respirators are met, and skin and eye exposures are unlikely.

This involves a full facepiece, air-purifying, canister-equipped respirator and chemical-resistant clothing.

It provides the same level of skin protection as Level B, but a lower level of respiratory protection.

Level D is primarily a work uniform. It provides no respiratory protection and minimal skin protec­

tion, and it should not be worn on any site where respiratory or skin hazards exist.

Exhibit II-8 illustrates these four levels of protection. For more information on this subject,

Appendix C outlines the protective equipment recommended for each level of protection.

Factors to be considered in selecting the proper level of protection include the potential routes of

entry for the chemical(s), the degree of contact, and the specific task assigned to the user. Activities

can also be undertaken to determine which level of protection should be chosen. The EPA and

NIOSH recommend that initial entry into unknown environments or into a confined space that has

not been chemically characterized be conducted wearing at least Level B, if not Level A, protection.

Routes of Entry

PPE is designed to provide emergency medical personnel with protection from hazardous materials

that can affect the body by one of three primary routes of entry: inhalation, ingestion, and direct

contact. Inhalation occurs when emergency personnel breathe in chemical fumes or vapors.

Respirators are designed to protect the wearer from contamination by inhalation but they must be

worn properly and fit-tested frequently to ensure continued protection. Ingestion usually is the result

of a health care provider transferring hazardous materials from his hand or clothing to his mouth.

This can occur unwittingly when an individual wipes his mouth with his hand or sleeve, eats, drinks,

or smokes a cigarette. Direct contact refers to chemical contact with the skin or eye. Skin is pro­

tected by garments, and full-face respirators protect against ingestion and direct eye contact. Mucous

membranes in the mouth, nose, throat, inner ear, and respiratory system may be affected by more

than one of these routes of entry. Many hazardous materials adhere to and assimilate with the

moist environment provided by these membranes, become trapped or lodged in the mucus, and are

subsequently absorbed or ingested.

29

Page 20: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-8 Levels of Protection

Level A Level B

Level C Level D

30

Page 21: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Chemical Protective Clothing (CPC)

Protective clothing is designed to prevent direct contact of a chemical contaminant with the skin or

body of the user. There is, however, no single material that will afford protection against all sub­

stances. As a result, multilayered garments may be employed in specific situations despite their neg­

ative impact on dexterity and agility. CPC is designed to afford the wearer a known degree of pro­

tection from a known type, a known concentration, and a known length of exposure to a hazardous

material, but only if it is properly fitted and worn correctly. Improperly used equipment can expose

the wearer to danger. Another factor to keep in mind when selecting CPC is that most protective

clothing is designed to be impermeable to moisture, thus limiting the transfer of heat from the body

through natural evaporation. This is a particularly important factor in hot environments or for strenu­

ous tasks since such garments can increase the likelihood of heat-related injuries. Research is now

underway to find lightweight suits that are breathable but still protective against a wide range of

chemicals. Cooling vests are sometimes used in warm weather situations to keep the body tempera­

ture normal, but with mixed results.

Essential to any protective ensemble are chemical resistant boots with steel toe and shank. Chemical

resistant inner and outer layered gloves must also be worn. Compatibility charts should be consulted

to determine the appropriate type of boot and gloves to use, since no one material presently provides

protection against all known chemicals. Wearing multiple layers of gloves impairs dexterity and

makes performing basic aspects of patient assessment (e.g., checking breathing, taking a pulse)

difficult without constant practice.

The effectiveness of CPC can be reduced by three actions: degradation, permeation, and penetration.

Chemical degradation occurs when the characteristics of the material in use are altered through

contact with chemical substances or aging. Examples of degradation include cracking and brittle­

ness, and other changes in the structural characteristics of the garment. Degradation can also result

in an increased permeation rate through the garment.

Permeation is the process by which chemical compounds cross the protective barrier of CPC

because of passive diffusion. The rate at which a compound permeates CPC is dependent on factors

such as the chemical properties of the compound, the nature of the protective barrier in the CPC, and

the concentration of the chemical on the surface of the protective material. Most CPC manufacturers

provide charts on the breakthrough time the time it takes for a chemical to permeate the material

of a protective suit for a wide range of chemical compounds.

Penetration occurs when there is an opening or a puncture in the protective material. These open­

ings can include unsealed seams, buttonholes, and zippers. Often such openings are the result of

faulty manufacture or problems with the inherent design of the suit. Protective clothing is available

in a wide assortment of forms, ranging from fully-encapsulated body suits to gloves, hard hats,

earplugs, and boot covers. CPC comes in a variety of materials, offering a range of protection against a

number of chemicals. Emergency medical personnel must evaluate the properties of the chemical

versus the properties of the protective material. Selection of the appropriate CPC will depend on the

specific chemical(s) involved, and on the specific tasks to be performed.

31

Page 22: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

RESPIRATORY PROTECTION

Substantial information is available for the correct selection, training, and use of respirators. The

correct respirator must be employed for the specific hazard in question. Material Safety Data Sheets

(if available) often specify the type of respirator that will protect users from risks. In addition,

manufacturers suggest the types of hazards against which their respirators can offer protection.

OSHA has set mandatory legal minimum requirements (29 CFR (1910.134)) for respiratory protec­

tion. In addition, NIOSH has established comprehensive requirements for the certification of respira­

tory protection equipment.

Personnel must be fit-tested for use of all respirators. Even a small space between the respirator

and you could permit exposure to a hazardous substance(s) by allowing in contaminated air. Anyone

attempting to wear any type of respirator must be trained and drilled in its proper use. Furthermore,

equipment must be inspected and checked for serviceability on a routine basis.

There are two basic types of respirators: air-purifying and atmosphere-supplying. Atmosphere-

supplying respirators include self-contained breathing apparatus (SCBA) and supplied-air respirators

(SAR).

Air-Purifying Respirators (APRs)

An air-purifying respirator purifies ambient air by passing it through a filtering element before

inhalation. The major advantage of the APR system is the increased mobility it affords the wearer.

However, a respirator can only be used where there is sufficient oxygen (19.5 percent) since it

depends on ambient air to function. In addition, APRs should not be used when substances with

poor warning properties are known to be involved or, if the agent is unknown, when environmental

levels of a substance exceed the filtration capacity of the canisters.

Three basic types of APRs are used by emergency personnel: chemical cartridges or canisters, dispos­

ables, and powered air-purifiers. The most commonly used APR depends on cartridges (Exhibit II-9)

or canisters to purify the air by chemical reaction, filtration, adsorption, or absorption. Cartridges and canisters are designed for specific materials at specific concentrations. To aid the user, manufacturers

have color-coded the cartridges and canisters to indicate the chemical or class of chemicals for which

the device is effective. NIOSH recommends that use of a cartridge not exceed one work shift.

However, if breakthrough of the contaminant occurs first, then the cartridge or canister must be

immediately replaced. After use, cartridges and canisters should be considered contaminated and

disposed of accordingly.

Disposable APRs are usually designed for use with particulates, such as asbestos, although some

are approved for use with other contaminants. These respirators are typically half-masks that

cover the face from nose to chin, but do not provide eye protection. Once used, the entire respira­

tor is usually discarded. This type of APR depends on a filter to trap particulates. Filters may also

be used in combination with cartridges and canisters to provide an individual with increased protec­

tion from particulates. The use of half-mask APRs is not generally recommended by emergency

response organizations.

32

Page 23: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-9 Chemical Cartridge Air-Purifying Respirator

Powered Air-Purifying Respirators (PAPRs) have the advantage of creating an improved facemask

seal, thus reducing the risk of inhalation injury. Air being blown into the mask can also have a

cooling affect. PAPRs come with either full facemasks or pullover hoods. Some individuals find the

hooded system to be more comfortable and less claustrophobic than the mask. According to OSHA

guidelines, men with beards can wear the hooded system but not the full facemask.

Atmosphere-Supplying Respirators

Atmosphere-supplying respirators consist of two basic types: the self-contained breathing apparatus

(SCBA), which contains its own air supply, and the supplied-air respirator (SAR), which depends on

an air supply provided through a line linked to a distant air source. Exhibit II-10 illustrates an

example of each.

Self-Contained Breathing Apparatus (SCBA)

A self-contained breathing apparatus respirator is composed of a facepiece connected by a hose to a

compressed air source. There are three varieties of SCBAs: open-circuit, closed-circuit, and escape.

Open-circuit SCBAs, most often used in emergency response, provide clean air from a cylinder to

the wearer, who exhales into the atmosphere. Closed-circuit SCBAs, also known as rebreathers,

recycle exhaled gases and contain a small cylinder of oxygen to supplement the exhaled air of the

wearer. Escape SCBAs provide air for a limited amount of time and should only be used for emer­

gency escapes from a dangerous situation. One disadvantage of all SCBAs is that they are bulky and

heavy, and can be used for only the period of time allowed by air in the tank.

The most common SCBA is the open-circuit, positive-pressure type. In this system, air is supplied to

the wearer from a cylinder and enters the facepiece under positive pressure. In contrast to negative-

pressure units, a higher air pressure is maintained inside the facepiece than outside. This affords the

SCBA wearer the highest level of protection against airborne contaminants since any leakage may

33

Page 24: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-10 Self-Contained Breathing Apparatus and Supplied-Air Respirators

force the contaminant out. When wearing a negative-pressure-type apparatus, there is always the

potential danger that contaminants may enter the facemask if it is not properly sealed. The use of a

negative-pressure SCBA is prohibited by OSHA under 29 CFR (1910.120(q)(iv)) in incidents where

personnel are exposed to hazardous materials.

Supplied-Air Respirators (SARs)

Supplied-air respirators differ from SCBAs in that the air is supplied through a line that is connected

to a source away from the contaminated area. SARs are available in both positive- and negative-

pressure models. However, only positive-pressure SARs are recommended for use at hazardous

materials incidents. One major advantage the SAR has over the SCBA device is that it allows an

individual to work for a longer period. In addition, SARs are less bulky than SCBAs. By necessity,

however, a worker must retrace his steps to stay connected to the SAR, and therefore cannot leave

the contaminated work area by a different exit. SARs also require the air source to be in close prox­

imity to the work area. In addition, personnel using an SAR must carry an immediately operable

emergency escape supply of air, usually in the form of a small, compressed air cylinder, for use in

case of an emergency.

34

Page 25: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

EMERGENCY DEPARTMENT PERSONNEL DECONTAMINATION

Decontamination is the process of removing or neutralizing harmful materials that have gathered on

personnel and/or equipment during the response to a chemical incident. Many incidents have occurred

involving seemingly successful rescue, transport, and treatment of chemically contaminated individuals

by unsuspecting emergency personnel who, in the process, contaminate themselves, the equipment,

and the facilities to which they bring the victim. Decontamination is of the utmost importance

because it:

ò Protects all hospital personnel by sharply limiting the transfer of hazardous materials from the

contaminated area into clean zones.

ò Protects the community by preventing transportation of hazardous materials from the hospital to

other sites in the community by secondary contamination.

ò Protects workers by reducing the contamination and resultant permeation of, or degradation to,

their protective clothing and equipment.

ò Protects other patients already receiving care at the hospital.

This section only addresses the steps necessary for dealing with worker decontamination. Patient

decontamination will be addressed in Section III, Patient Management. It should be stressed that to

carry out proper decontamination, personnel must have received at least the same degree of training

as required for workers who respond to hazardous materials incidents. The design of the decontamina­

tion process should take into account the degree of hazard and should be appropriate for the situation.

For example, a nine-station decontamination process need not be set up if only a bootwash station

would suffice.

Avoiding contact is the easiest method of decontamination that is, not to get the material on the

worker or his protective equipment in the first place. However, if contamination is unavoidable, then

proper decontamination or disposal of the worker s outer gear will be necessary. Segregation and

proper disposal of the outer gear in a polyethylene bag or steel drum will be necessary until thorough

decontamination is completed. With extremely hazardous materials, it may be necessary to dispose

of equipment as well.

Physical decontamination of protective clothing and equipment can be achieved by several different

means. These all include the systematic removal of contaminants by washing, usually with soap and

water, and then rinsing. In rare cases, the use of solvents may be necessary. There is a trend toward

using disposable clothing (e.g., suits, boots, gloves) and systematically removing these garments in a

manner that precludes contact with the contaminant. The appropriate decontamination procedure will

depend on the contaminant and its physical properties. Thoroughly researching the chemicals involved

and their properties, or consultation with an expert, is necessary to make these kinds of decisions.

Care must be taken at all times to ensure that the decontamination methods being used do not intro­

duce fresh hazards into the situation. In addition, the residues of the decontamination process must

be treated as hazardous wastes. The decontamination stations and process should be confined to the

Contamination Reduction Zone (see Exhibit II-11). Steps for personnel decontamination are outlined

in Exhibit II-12, and the technical decontamination process is discussed below.

35

Page 26: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Technical Decontamination Process for Hospital Personnel

Personnel should remove protective clothing in the following sequence.

1. Remove tape (if used) securing gloves and boots to suit.

2. Remove outer gloves, turning them inside out as they are removed.

3. Remove suit, turning it inside out and folding it downward. Avoid shaking.

4. Remove boot/shoe cover from one foot and step over the clean line. Remove other boot/shoe cover and put that foot over the clean line.

5. Remove mask. The last person removing his/her mask may want to wash all masks with soapy water before removing his/her suit and gloves. Place the masks in plastic bag and hand the bag over the clean line for placement in second bag held by another staff member. Send bag for decontamination.

6. Remove inner gloves and discard them in a drum inside the dirty area.

7. Secure the dirty area until the level of contamination is established and the area is properly cleaned.

8. Personnel should then move to a shower area, remove undergarments and place them in a plastic bag. Double-bag all clothing and label bags appropriately.

9. Personnel should shower and redress in normal working attire and then report for medical surveillance.

COMMUNICATIONS

Effective communications are essential to maintaining incident control. These include a dedicated

radio frequency and a sufficient number of radios for distribution to all participating agencies.

Another network should link the onsite command post to support groups, such as the Poison Control

Center and the Health Department. Other networks that may have to be activated include one linking

the hospital emergency department to EMTs and one dedicated for use by the teams in the Exclusion

and Contamination Reduction Zones. When an Incident Command System is activated, one person is

often assigned to manage communications.

36

Page 27: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-11 NIOSH/OSHA/USCG/EPA Recommended Zones

37

Page 28: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Exhibit II-12 Nine-Step Personnel Decontamination Plan

38

Page 29: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

SELECTED BIBLIOGRAPHY

American Conference of Governmental Industrial Hygienists. 1988. Guidelines for the Selection of Chemical Protective Clothing. Cincinnati, OH.

American Academy of Pediatrics. 1994. Handbook of Common Poisonings in Children. 3rd ed. Elk

Grove Village, IL.

Borak, J., M. Callan, and W. Abbott. 1991. Hazardous Materials Exposure-Emergency Response and Patient Care. Englewood Cliffs, NJ: Brady.

Bowen, J. E. 1995. Emergency Management of Hazardous Materials Incidents. Quincy, MA:

National Fire Protection Association.

Bronstein, A.C. and P.L. Currance. 1994. Emergency Care for Hazardous Materials Exposure. 2nd

ed. St. Louis, MO: Mosby.

Budavari, S., A. Smith, P. Heckelman, and J. Kinneary. 1996. The Merck Index: An Encyclopedia of Drugs, Chemicals, and Biologicals. 12th ed. Chapman & Hall.

Chemical Manufacturers Association (CMA) and the Association of American Railroads. 1987.

Terms for Personal Protective Equipment. Washington, DC: CMA.

Clayton, G.D. and F.E. Clayton. 1994. Patty s Industrial Hygiene and Toxicology. 4th ed. New York,

NY: John Wiley and Sons.

Currance, P.L. and A.C. Bronstein. 1999. Hazardous Materials for EMS. St. Louis, MO: Mosby.

Ellenhorn, M.J. and D.G. Barceloux. 1997. Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. New York, NY: Elsevier.

Forsberg, K. and S.Z. Mansdorf. 1993. Quick Selection Guide to Chemical Protective Clothing. 2nd

ed. New York, NY: Van Nostrand Reinhold.

Goldfrank, L.R. 1998. Goldfrank s Toxicological Emergencies. 6th ed. Stamford, CT: Appleton and

Lange.

Grant, W.M. and J.G. Schuman. 1993. Toxicology of the Eye. 4th ed. Springfield, IL: Charles C.

Thomas.

Hayes, A.W. (ed.). 1994. Principles and Methods of Toxicology. 2nd ed. Books on Demand.

Hodgson, E. and P.E. Levi. 1997. A Textbook of Modern Toxicology. 2nd ed. Stamford, CT: Appleton

and Lange.

Klaassen, C.D., M.O. Amdur, and J. Doull (eds.). 1996. Casarett and Doull s Toxicology: The Basic Science of Poisons. 5th ed. McGraw-Hill Health Professions Division.

Levine, S.P. and W.F. Martin (eds.). 1993. Protecting Personnel at Hazardous Waste Sites. 2nd ed. Boston, MA: Butterworth Publishers.

39

Page 30: Managing Hazardous Materials Incidents - Agency for Toxic ... › mhmi-v2-2.pdf · Hazardous Industrial Chemicals, United Nations Hazard Class Numbers, and either hazard class wording

Lu, F.C. 1996. Basic Toxicology: Fundamentals, Target Organs, and Risk Assessment. 3rd ed. Taylor

& Francis, Inc.

National Emergency Training Center. 1998. Guidelines for Public Sector Hazardous Materials Training. Emmitsburg, MD: HMEP Curriculum Guidelines.

National Fire Academy and National Emergency Training Center. 1985. Recognizing and Identifying Hazardous Materials. Capitol Heights, MD: National Audio-Visual Center.

Proctor, N.H., J.R. Hughes, and M.L. Fishman. 1989. Chemical Hazards of the Workplace. 2nd ed.

New York, NY: Van Nostrand Reinhold.

Rom, W. 1992. Environmental and Occupational Medicine. 2nd ed. Boston, MA: Little, Brown.

Sax, N.I. 1992. Dangerous Properties of Industrial Materials. 8th ed. New York, NY: Van Nostrand

Reinhold.

Schwope, A.D., P.P. Costas, J.O. Jackson, and D.J. Weitzman. 1987. Guidelines for the Selection of Chemical Protective Clothing. 3rd ed. Cincinnati, OH: American Conference of Governmental

Industrial Hygienists.

Sidell, F.R. and D.R. Franz (eds.). 1997. Medical Aspects of Chemical and Biological Warfare. U.S.

Department of the Army. Washington, DC: Borden Institute.

Stutz, R. and S. Ulin. 1993. HAZTOX EMS Response For Hazardous Materials Incidents. Miramar,

FL: GDS Communications.

Sullivan, J.B., Jr. and G.R. Krieger. 1992. Hazardous Materials Toxicology: Clinical Principles of Environmental Health. Baltimore, MD: Williams & Wilkins.

Tokle, G. (ed.). 1993. Hazardous Materials Response Handbook. 2nd ed. Quincy, MA: National Fire

Protection Association.

U.S. Department of Defense, U.S. Army, USAMRICD Chemical Casualty Division. 1998. Medical Response to Chemical Warfare and Terrorism. 3rd ed. Edgewood, MD.

U.S. Environmental Protection Agency, Region VII. 1989. Chemical Response Planning and Operations. Washington, DC: Environmental Protection Agency.

U.S. Federal Emergency Management Agency and U.S. Fire Administration. 1999. Hazardous Materials Guide for First Responders. Washington, DC: Government Printing Office.

40